Timewarp

Timewarp

Although The Foundry’s amazing Furnace plug-ins are
not, at this writing, available for After Effects, Adobe
licensed one component of Furnace, the retiming tool
known as Kronos, to provide the technology used in Pixel
Motion and Timewarp. Pixel Motion is an automated setting
described earlier, and Timewarp adds a set of controls
to allow you to improve on its result using the same basic
technology.
Timewarp works by calculating the motion in the footage
in order to generation motion vectors; these describe how
each pixel moves from frame to frame. With an accurate
analysis it is then possible to generate an image made up
of those same pixels, interpolated along those vectors, with
different timing.
Timewarp is just like Time Remap in the following ways:
. It can be used to speed up, slow down, or dynamically
animate the timing of a clip.
. It incorporates the same three Frame Blending modes
(Whole Frames, Frame Mix, and Pixel Motion) as are
available to Time Remap in the Timeline settings; these
live in Timewarp’s Method menu.
. Time Remap keyframes can even be transferred directly
to Timewarp, but it requires an expression (see note)
because one uses frames and the other seconds to measure
time.
However, used with the default Pixel Motion Method
setting, Timewarp goes beyond Time Remap plus Frame
Blending with the same setting in a couple of ways:
. Enable Motion Blur toggle kicks in when footage is
sped up to add motion blur.
. Tuning section lets you refi ne the automated results of
Pixel Motion.
Timewarp is most typically used to slow footage down,
which requires one extra bit of setup or the layer ends
short. Enable Time Remapping and extend the layer across
your Comp; the Time Remap settings don’t even matter as
Timewarp will override them.